ESPE Abstracts (2014) 82 P-D-1-3-125

Impairment of Adipose Tissue in Prader-Willi Syndrome Rescued by GH Treatment

Thomas Cadoudala,b, Gwenaelle Dienec, Coralie Sengenesa,b, Catherine Molinasc,e, Flavie Desneulind, Sanaa Eddirye, Francoise Conte Auriold,e, Daniele Daviauda,b, Anne Bouloumiea,b, Jean Pierre Sallesc,e, Philippe Valeta,b & Maithe Tauberc,e

aINSERM, UMR 1048, Institut des Maladies Métaboliques et Cardiovasculaires I2MC, Toulouse, France; bUniversité Paul Sabatier, UMR 1048, Toulouse, France; cUnité d’Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader–Willi, Hôpital des Enfants, Toulouse, France; dAxe Pédiatrique du CIC 9302/INSERM, Hôpital des Enfants, Toulouse, France; eINSERM, UMR 1043, Toulouse, France

Background: Prader–Willi syndrome (PWS) results from abnormalities in the genomic imprinting process leading to hypothalamic dysfunction with an alteration of GH secretion. PWS is associated with early morbid obesity and short stature which can be efficiently improved with GH treatment.

Objective and hypotheses: Our aims were to highlight adipose tissue structural and functional impairments in young children with PWS and to study the effect of GH treatment.

Method: Adipose tissue (AT) biopsies were obtained during scheduled surgeries from control lean children (n=15, age=40.6±5.9 months), untreated lean PWS children (n=7, age=19.6±3.8 months) or PWS children under GH treatment for at least 1 year (n=8, age=103.6±20.1 months). This study is part of a prospective national multicenter study evaluating both in vivo and in vitro GH sensitivity in PWS approved by the Local Ethical Committee (no. EUDRACT 2008-004612-12).

Results: Analysis of biopsies revealed that in stromal vascular fraction of AT, adipose progenitor cells (CD34+/CD31/CD14 cells) were significantly reduced in untreated PWS AT when compared to control samples (75 000 cells/g of control AT to 40 000 cells in the same amount of PWS tissue). GH treatment tended to restore this population of progenitor cells in AT. Isoprenaline strongly activated lipolysis in control adipocytes (maximal 12-fold increase of basal lipolysis) whereas this β-adrenergic agonist effect was partially lost in adipocytes from PWS children (maximum fourfold activation). In contrast, isoprenaline-induced stimulation over basal lipolysis was stronger in GH-treated than untreated PWS adipocytes.

Conclusion: Herein, we report adipose tissue dysfunctions in children with PWS which may be partially restored by GH treatment.